Diagnostic efficacy of dual energy CT in differentiating intracerebral hemorrhage from iodinated contrast material staining

Purpose: To evaluate the efficacy of dual energy CT in early differentiating intracerebral hemorrhage from iodinated contrast material staining. Materials and methods: In this study 46 patients with acute stroke who had undergone recent mechanical thrombectomy and intravenous administration of iodinated contrast material were evaluated on dual energy CT scan (DECT) at 80 and 150kV, to differentiate areas of hyperattenuation secondary to contrast material staining from those representing intracerebral hemorrhage (ICH). Mixed images, virtual unenhanced images (VNC) and iodine overlay maps (IOM) were obtained. Follow up imaging after 24 and 48 hours on conventional CT were used as the standard of reference. A hyperattenuation only seen on VNC image was classified as hemorrhage. A hyperattenuation only seen on iodine map was deemed as contrast. Results: Mixed images obtained with Dual energy CT showed intra-parenchymal hyperattenuation in 46 patients. Out of these 46 hyperattenuations, iodine staining(n=31,67%), ICH(n=7,15%) and both(n=8,17%)--2 of the 8 areas of hyperattenuation on both VNC and IOM were due to mineralization. The sensitivity, specificity, and accuracy of Dual energy CT in the identifying hemorrhage was calculated as 100 %( 7of 7areas), 93 %( 31 of 33 areas) and 95 %( 38 of 40 areas) respectively. Conclusion: DECT has high sensitivity and specificity and allows accurate differentiation between ICH and iodine staining after recent stroke intervention without employing extra radiation. Hence, allows prompt administration of anti- platelet therapy in case of no ICH, when clinically indicated.